Prototype teknologi siluman (stealth) material organik penyerap gelombang radar dari komposit polimer chitosan-hidroksiapatit untuk aplikasi peralatan militer wilayah perbatasan

Border regions in Indonesia are still often hit problems with other countries , and in other words it indicates weak military defense systems in the border area . Therefore, Indonesia needs to deploy some special forces on the frontier that uses advanced technology , one of them is the stealth technology . Radar absorbing material plays an important role in this technology . Chitosan and h ydroxyapatite believed to resemble a good combination of new organic materials that can be developed as a radar absorbing material . The purpose of this study is to develop a prototype of organic radar absorbing material from chitosan -hydroxyapatite polymer composite . Quality characteristics of the material being analyzed are solution viscosity analysis , FTIR , SEM , material thickness , tensile strength . Ability of material to absorb radar waves was analyzed with reflection loss measurement . The prototype resembles a thin, transparent plastic sheet with a yellowish brown color . Values of thickness ranged from 0 .14 to 0.17 mm . This material has a tensile strength values ranged from 1.41 ± 2.82 to 159.33 ± 106.33 kPa . SEM analysis showed a porous and homogeneous structure marked by good interaction between chitosan , PVA , and hydroxyapatite . Value of radar absorption by prototype shown with increasing the value of reflection loss . The optimum values obtained in the film with a mixture of chitosan prototype 2 %, 5 % PVA , and 0.04 gram hydroxyapatite with an average value of reflection loss -32.0907 ± 4.0763 dB . Keywords : chitosan, hydroxyapatite, polyvinyl alcohol, radar absorbing material, reflection lo ss